Apparatus and methods are known for accessing a patient's vasculature percutaneously, e.g., to perform a procedure within the vasculature, and for sealing the puncture that results after completing the procedure. For example, a hollow needle may be inserted through a patient's skin and overlying tissue into a blood vessel. A guide wire may be passed through the needle lumen into the blood vessel, whereupon the needle may be removed. An introducer, procedural, or femoral sheath may then be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to one or more dilators. A catheter or other device may be advanced through the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate accessing and/or introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss.
Wounds such as arteriotomies can arise in the blood vessel from these various medical procedures, especially for blood vessels acting as sites for catheter insertion during diagnostic and/or interventional catheterization. After such procedures have been completed, the arteriotomy that was created as an access point during the medical procedure needs to be closed.
Upon completing the procedure, the device(s) and introducer sheath may be removed, leaving a puncture extending between the skin and the vessel wall. To seal the puncture, external pressure may be applied to the overlying tissue, e.g., manually and/or using sandbags, until hemostasis occurs. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a medical professional's time. It is also uncomfortable for the patient, and may require the patient to remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Vascular closure devices can be used to achieve hemostasis (e.g., sealing) of small holes that are formed in a blood vessel (either artery or vein) as the result of an intravascular procedure (e.g., cannulation). Such procedures may be for diagnosis, drug delivery, therapy (e.g., stent placement or angioplasty) and the like. The procedures involve the formation of a small incision in the wall of a vessel to gain access to the intravascular space. This incision, the vascular puncture or arteriotomy, must be closed at the completion of the procedure. Rapid hemostasis at the vascular puncture is ideal, as it reduces patient complications, improves time to patient ambulation and time to hospital discharge.
For example, a mechanical based device can be utilized for vascular closure. A percutaneous surgical device can comprise a combination wound suturing and crimping and cutting device. The combined device may locate a vessel wound and pass suture through the vessel walls surrounding the wound. Then, the crimping and cutting portion may detach, the suturing portion may be removed, and the crimping and cutting portion may be located to the wound site to apply a fastener (e.g., a ferrule).
Another mechanical based device can have two components: a needle advancing apparatus slidable longitudinally along a catheter to advance needles into a tissue membrane, such as a blood vessel wall, around an opening in the membrane; and, a suture retrieval assembly insertable through the catheter beyond a distal side of the tissue membrane. The needle advancing apparatus advances suture through the tissue wall. The suture retrieval assembly grabs the suture on the distal side of the tissue membrane for extraction thereof through the opening in the tissue membrane.
Such mechanical approaches tend to require precise positioning within the tissue tract, typically provide point (instead of a continuum of tissue purchase) support, and lead to permanent foreign-body implants that interfere with subsequent catheterization at the same vascular site. Additionally, a purely mechanical support of the wound could lead to implanting substantially non-absorbable foreign material that provides only point-support to the wound lips. In addition, purely mechanical closures still can leave behind open micro-spaces, or small gaps, between the sutures that are not entirely closed.
Previously (and currently, in some cases), manual compression was the main method for closing the vascular puncture. This could involve extended periods of manual pressure, clamping, exogenous weights, etc., applied directly to the site of the vascular puncture. As hemostasis could take 20 to 60 minutes, patients often experienced discomfort, and extended periods of bed rest were required.
In addition to, or in place of manual compression, vascular closure devices were developed to reduce the time to achieve hemostasis. Some such devices used sutures or collagen plugs to seal the vascular puncture. However, many such devices result in an intravascular component being retained within the vessel, which can lead to future complications.
More recently biodegradable materials have been employed to seal the vascular puncture and, due to their dissolution over time, improve patient comfort and reduce complications. Because rapid hemostasis can improve patient outcome and reduce medical costs, further improvements in vascular sealants would be beneficial.
Though presently in use, many current sealant technologies facilitate hemostasis of a wound puncture by physically clogging the tissue tract. This physical occlusion replaces manual compression, but certain of such polymeric sealants have a relatively weak polymer network integrity, which can increase time to hemostasis.
Various biological approaches to vascular closure have been used such as a device and method that includes inserting a vessel plug or sealant into the incision or puncture until the distal end of the vessel plug is adjacent to the outer lumen of the blood vessel. The vessel plug is positioned so that it does not obstruct the flow of fluid through the blood vessel or target organ. The precise positioning of the vessel plug in the incision or puncture is accomplished through the use of a balloon catheter or a cylindrical insertion assembly having a proximal plunger member associated therewith. Another biological closure can deploy a collagen plug to seal the closure. In order to block the collagen from entering the vessel, a footplate is installed on the interior of the blood vessel. The footplate is held in place with a suture.
In one instance, a vascular closure device can include two synthetic polyethylene glycol (“PEG”) polymer powders that are mixed with appropriate buffers and injected through a femoral sheath at an arteriotomy site, e.g., as disclosed in U.S. Pat. No. 7,316,704. Accordingly, apparatus and methods for sealing a puncture through tissue would be useful. In particular, improving the efficacy (e.g., speed and/efficiency) of sealing a puncture would be useful.